When you analyze and fix for color balance, you have to actually select Balance Color (or command-option-B) to get FCPX to actually "act" on the clip.
Until you do, then the color is only Analyzed. You must opt to apply the "Fix".
You will get a Balance Color entry in the Effects browser which allows you to select a Method of balance and a checkbox with the option to turn it on or off.
I recommend actually selecting White Balance and use the eyedropper tool to select pixels that would normally be absolutely grayscale (concrete, asphalt, marble, etc. — it doesn't actually have to be white). A lot of times, what is white in video is just "blown out" and not a good reference source.
You will find other similar options regarding audio effects.